use strict;
use warnings;

my %database;
my ($id,$user,$password,$display);
while(<DATA>){
        chomp;
        ($id,$user,$password,$display)=split /\|/;

        $database{$id}=[] unless exists $database{$id};    #avoid primary key duplications.
        push @{$database{$id}}, ($user, $password,$display);
        }
foreach my $id (sort keys %database){
        print "ID $id:\nINFO: @{$database{$id}}\n";
        print "\n";
        }

__DATA__
UserID001|username1|password1|displayname1|
UserID002|username2|password2|displayname2|
UserID003|username3|password3|displayname3|